In a scroll compressor comprising a pair of a fixed scroll member and a revolving scroll member, which are engaged with each other to form a compression chamber, even in the case that the fixed scroll member and the revolving scroll member have a fine process error or an assembly error, conventionally used has been a driven crank mechanism for certainly making laps contact with each other to minimize a leakage of compression gas so as to secure compression efficiency in accordance with the error. The driven crank mechanism is arranged to be able to make a revolving radius of the revolving scroll member variable. The driven crank mechanism uses centrifugal force, compression reaction force of a gas or the like to drive the revolving scroll member to perform revolutionary turning so that a lap of the revolving scroll member would be pushed against a lap of the fixed scroll member.
Further, in order to prevent self rotation of the revolving scroll member in driving the revolving scroll member to perform revolutionary turning around the fixed scroll member as described above, provided is a self rotation preventing mechanism between the revolving scroll member and a support member of the revolving scroll member or between the revolving scroll member and the fixed scroll member. As a typical example of the self rotation preventing mechanism, named can be an Oldham ring mechanism, a pin-and-ring mechanism and such. Moreover, Patent Citation 1 discloses a scroll compressor comprising a drive mechanism of the revolving scroll member used as the driven crank mechanism, the scroll compressor wherein a pin-and-ring type self rotation preventing mechanism is used as the self rotation preventing mechanism.
On the other hand, put to practical use has been a pin-and-ring type self rotation preventing mechanism in a scroll compressor using the driven crank mechanism and the pin-and-ring type self rotation preventing mechanism in combination, the pin-and-ring type self rotation preventing mechanism wherein two of pins and rings provided in plural places simultaneously become into contact to prevent an operation of the driven crank mechanism from being limited, a maximum displacement in a direction of self rotation of the revolving scroll member (a center distance between a center of the ring hole of the revolving scroll member and a center of the self rotation preventing pin) R, the maximum displacement being determined on the basis of engagement of a ring hole of the revolving scroll member, a self rotation preventing ring fitted to the ring hole and a self rotation preventing pin, is set at a large value with respect to a theoretical revolving radius of the revolving scroll member so as to include a revolving radius variable by means of the driven crank mechanism for the purpose of preventing an excessive load from operating on one of the self rotation preventing pins located in two places, the one located in a self rotation moment direction, and a location for providing the self rotation preventing pin is offset in accordance with the setting to provide pins and rings for preventing self rotation of the revolving scroll member in plural places (Patent Citation 2).    Patent Citation 1: Japanese Unexamined Patent Application, Publication No. Hei-11-13657    Patent Citation 2: Japanese Unexamined Patent Application, Publication No. 2007-297950